Low cost calculator providing serial printing and a bi-quinary system for amount entry

ABSTRACT

A ten-key printing calculator having a pin carriage and a plurality of ordinally arranged accumulator wheels utilizes a single print hammer, a single printing element, and a single accumulator actuator for serially printing and accumulating keyboard-entered amounts, and for serially reading and printing stored amounts, the single printing element and accumulator actuator being combined in a traversing carrier that translatably cooperates with the preset pin carriage for printing keyboardentered amounts, and with the plurality of accumulator wheels to both accumulate keyboard-entered amounts and to read and print amounts stored in the accumulator. The traversing carrier is provided with a pair of differentially geared indexing slides responsive to the preset position of five pins arranged in each column of the pin carriage, and to the preset positioning of five limit stops associated with each order of the accumulator, such arrangement presenting a bi-quinary system of amount entry and read-out.

United States Patent [151 3,687,361

Paige 1 Aug. 29, 1972 [54] LOW COST CALCULATOR Primary Examiner-Stephen J. Tomsky [72] Inventor: Walter Griffin Paige, Pasadena,

Calif.

[73] Assignee: Burroughs Corporation, Detroit,

Mich.

[22] Filed: May 5, 1971 [21] Appl. No.: 140,373

[52] US. Cl ..235/60 P, 101/93 C, 235/60 TK [51] Int. Cl ..G06c 11/04, B4j 5/08 [58] Field of Search ..235/60 P, 60 TK, 60.38, 60.39, 235/6040, 6046; 101/93 R, 93 C [56] References Cited UNITED STATES PATENTS 1,910,201 5/1933 Cordt ..235/60 P 3,406,625 10/1968 Chammess et a1. ..101/93 C 3,429,414 2/1969 Bradbury ..101/93 C 3,594,548 7/1971 Abbiati ..235/60 P PROVIDING SERIAL'PRINTING AND A BI-QUINARY SYSTEM FOR AMOUNT ENTRY Attorney-1(enneth L. Miller and Edwin W. Uren [5 7 ABSTRACT A ten-key printing calculator having a pin carriage and a plurality of ordinally arranged accumulator wheels utilizes a single print hammer, a single printing element, and a single accumulator actuator for serially printing and accumulating keyboard-entered amounts, and for serially reading and printing stored amounts, the single printing element and accumulator actuator being combined in a traversing carrier that translatably cooperates with the preset pin carriage for printing keyboard-entered amounts, and with the plurality of accumulator wheels to both accumulate keyboard-entered amounts and to read and print amounts stored in the accumulator. The traversing carrier is provided with a pair of differentially geared indexing slides responsive to the preset position of five pins arranged in each column of the pin carriage, and to the preset positioning of five limit stops associated with each order of the accumulator, such arrangement presenting a bi-quinary system of amount entry and read-out.

28 Claims, 22 Drawing Figures Patented Aug. 29, 1972 3,687,361

11 Sheets-Sheet 1 FIG.I

- INVENTOR. 5 I WALTER GRIFFIN PAIGE AGENT .11 Sheets-Sheet 2 F/ll/l/I/I/I/l/I fill/riff!!! llllflllflllllflylfffflVII!!- Patented Aug. 29, 1972 .11 Sheets-Sheet 4 FIGS FIG-,5

Patgnhd Aug. 29, 1972 3,687,361

' .11 Sheets-Shoat 5' Patented Aug. 29, 1972 .ll Sheets-Shoat 6 FIG.9

Patented Aug. 29, 1972 i Y 3,687,361

.11 Sheets-Shoat 8 FIG. l2

Patented Aug. 29, 1972 .11 Sheets-Shoot 9 Pmnud Aug. 29, 1972 .11 Sheets-Sheet 1o LOW COST CALCULATOR PROVIDING SERIAL PRINTING AND A BI-QUINARY SYSTEM FOR AMOUNT ENTRY BACKGROUND OF THE INVENTION calculators in homes and small businesses prohibitive.

The relatively high price of known mechanical calculators is attributable to their complexity and the multiplicity of parts that are required to achieve acceptable standards of speed and performance, such standards generally requiring the simultaneous accumulation and printing of entered or stored amounts. With the advent of electronic calculators that are capable of computing and printing amounts at speeds considerably higher than was previously thought possible, many manufacturers have re-evaluated the role of the mechanical calculator and have either discontinued their manufacture or attempted to reduce their cost to a point where they might appeal to a lower priced and broader market in which speed of computation and printing is relegated to a position of lesser importance.

To achieve previous standards of speed and performance, mechanical calculators have historically provided a multiplicity of similarly constructed parts, particularly in the keyboard, printing and accumulating areas. Initially the keyboards of such calculators have provided a plurality of keyboard columns wherein the values 1 through 9 have been repetitiously represented, the number of key columns corresponding to the listing capacity of the machine. In like manner the printing sections of these machines have provided a plurality of identical indexing slides, type bars and print hammers; and the accumulating sections have provided a plurality of actuating racks, accumulating wheels, and carry pawls, the number of such type bars, print hammers and actuating racks corresponding to the number or ordinal digits that characterize the full capacity of the machine.

Later known mechanical calculators provided a reduced number of keyboard keys, in the transition from the so-called full keyboard calculator to the lO-key calculator. Whereas known l0-key calculators have provided a single keyboard key for each of the values 0 through 9, along with various operation control keys, the customary plurality of indexing slides, type bars, and print hammers were retained. In order to provide cooperation between the single set of numeric keys of the keyboard with the plurality of indexing slides, type bars and print hammers, it was additionally necessary to introduce the well known pin carriage, as well as its associated escapement means for leftwardly advancing the pin carriage in stepwise fashion upon each depression of a numeric key. These well known pin carriages have historically provided a plurality of depressible pins arranged in vertical columns and horizontal rows, the number of columns corresponding to the listing capacity of the machine, and the number of rows corresponding to the values 0 through 9.

Although the lO-key calculator represented a moderate reduction in manufacturing costs, significant cost reduction could not be realized in view of the retention of the conventional number of indexing slides,

type bars, print hammers, and actuating racks, and the introduction of the pin carriage with its full complement of depressible pins. It was accordingly recognized that the broader small business and home markets could not be fully exploited without effecting a further reduction in the number of parts required for computing and printing.

SUMMARY OF THE INVENTION In recognition of the competitive disadvantage imposed upon mechanical calculators by higher speed electronic calculators, and the resultant re-evaluation of the role of the mechanical calculator in the market place, further impetus was provided to develop a low cost calculator that would appeal to small businesses and home users, and thereby bring the convenience of mechanical computation and printing within easy reach of a broader market.

It is accordingly an object of the present invention to provide a mechanical printing calculator that can be produced at minimal cost and sold at a price within reach of small businessmen and home owners.

It is another object of the present invention to provide a mechanical printing calculator that will prove reliable for calculating and printing purposes, and wherein the accuracy of the computed result is paramount to the speed withwhich the result is provided.

It is a still further object of the invention to provide a mechanical printing calculator that comprises a minimal number of parts, and wherein the unnecessary duplication of similarly constructed parts is eliminated.

It is yet another object of the present invention to devise a printing mechanism wherein the customary pluralities of indexing slides, type bars, and print hammers are not present, and wherein a single actuating rack is employed to sequentially cooperate with the various orders of the accumulating pinions or gear wheels.

It is still a further object of the invention to effect a significant reduction in the manufacturing cost of the pin carriage section of lO-key calculators, by holding the number of depressible pins thereof to a minimum.

An important aspect of the invention is the combination of a single printing element and a single actuating output pinion on a translatable carrier, the carrier being biased towards a rightmost home position and translatable from right to left to effect the serial printing of amounts beginning with the least significant digit and ending with the most significant digit, and to coincidentially provide sequential cooperation with the various orders of the accumulator wheels.

Another important aspect of the invention is the inclusion in such translatable carrier of a pair of biased indexing slides associated with the single printing element, and differential gearing associated therewith, the

differential restraint of the biased slides in cooperation with the differential gearing being effective to position selected type characters of the single printing element in printing position, and to correspondingly advance the single actuating output pinion.

Still another aspect of the invention is the provision of a pin carriage having the customary number of vertical columns, but wherein each column is provided with a total of five identically formed depressible pins, one

of the pins in each column providing restrainable cooperation with one of the indexing slides of the carrier, and the remaining four pins providing restrainable cooperation with the other of the indexing slides. The five pins in each vertical column of the pin carriage, in cooperation with the pair of biased indexing slides of the carrier, are effective to select the type characters through 9 of the single printing element.

Still another aspect of the invention is the use of accumulator cam wheels associated with the various orders of the accumulator, and a plurality of biased slides associated with the accumulator cam wheels, each of the slides being provided with a predetermined number of step-like limits. The purpose of these step-like limits is-to differentially restrain the biased activation of the pair of indexing slides of the carrier, in like manner to the five pins in each vertical column of the pin carriage, to thereby select the type characters of the single printing element during total and subtotal operations. The arrangement is such that the accumulator slides are resiliently activated to limit against the cam surfaces of the accumulator cam wheels, and to thereby position the step-like limits thereof into-blocking relationship with the pair of biased indexing slides of the printing element carrier.

A particular functional aspect of the low cost calculator is that the printing element carrier is drivenly activated in step-wise fashion from right to left during listing, accumulating, subtotaling and totaling operations, the single printing element thereof serving to serially print the values that have been stored, or are to be entered in the various orders, as selected either by the corresponding orders of the accumulator slides or pin columns of the pin carriage, the output actuator pinion of the carrier serving to sequentially advance the corresponding orders of the accumulator wheels during accumulating operations.

A still further aspect of the invention is the use of a single printing hammer extending the full length of the printing line, such hammer being repetitiously activated during the right to left excursion of the carrier to thereby effect printing in the various orders according to the selectively positioned type characters of the single printing element.

BRIEF DESCRIPTION OF THE DRAWINGS These and other objects, aspects and advantages of the invention will be more clearly understood from the following description when read in conjunction with the accompanying drawings, in which:

FIG. 1 is a plan view showing the various operating sections of the inventive IO-key calculator;

FIG. 2 is a sectional elevation of the preferred embodiment of the invention as viewed from the left side thereof and showing the relationship of the main operating sections;

FIG. 3 is a rear view of the printing element carrier which combines the single printing sector and the single accumulator actuator of the inventive calculator, and showing also various details of carrier translating means and type character selection means;

FIG. 4 is a partial rear view of the printing element carrier of FIG. 3 with portions deleted therefrom;

FIG. 5 is a left side sectional elevation of the printing element carrier showing one of the differentially geared indexing slides in detail;

FIG. 6 is a left side sectional elevation of the printing element carrier showing the detailed construction of the other of the differentially geared indexing slides;

FIG. 7 is a top view of the printing element carrier showing some of the details of its differential gearing, and showing also various details of the type character selection means;

FIG. 8 is a fragmentary sectional elevation of the printing element carrier showing the arrangement of the differential gearing which is effective for selectively positioning the type characters of the single printing sector in printing position;

FIG. 9 is a view taken along the line 9-9 of FIG. 8 and showing various details of the differential gearing of the printing sector and printing element carrier;

FIG. 10 is a fragmentary left side sectional elevation of the preferred embodiment of the invention showing various details of the printing element carrier, the type character selection means, the pinions and gear wheels of the accumulator, and the drive shaft actuating means;

FIG. 10A is a partial perspective view showing the relationship of the transfer pinions and carry wheels of the accumulator, as well as the means by which carries are transferred into higher order accumulator wheels;

FIG. 11 is a front sectional elevation showing details of a first drive shaft of the inventive calculator, and

cams thereof associated with type character selection means, add-subtract control means, and print hammer control means;

FIG. 12 is a left side sectional elevation similar to FIG. 2 with certain parts deleted and other parts added to illustrate the relationship of the cam wheels of the accumulator and the accumulator slides associated therewith;

FIG. 13 is a left side sectional elevation similar to FIG. 12 and showing the cam wheels and associated slides of the accumulator in greater detail;

FIGS. 14A, B and C are left side views of an accumulator cam wheel with the surfaces of the cam segments identified with the digit values that are read thereby;

FIG. 15 is an exploded perspective view of the means by which the accumulator wheels are cleared and returned to their zero settings;

FIG. 15A is a partial left side view of a reset gear of the accumulator showing the pivotal pawl thereof and its relationship to the shaft providing rotational support for the reset gears;

FIG. 16 is a left side perspective view of the accumulator reset mechanism in its deactivated state;

FIG. 17 is a left side perspective view of the reset mechanism of FIG. 16 as shown in its activated state; and

FIG. 18 is a view taken along the line 18-48 of FIG. 8 and showing the collar and sleeve arrangement of the printing element carrier.

DETAILED DESCRIPTION OF THE INVENTION The principal operating sections of the preferred embodiment of the low cost calculator may be generally identified with reference to FIG. 2. A continuously rotating motor 3 is shown in belted and geared relationship with a first drive shaft 5 and a second drive shaft 7, such drive shafts providing control over the various operating areas as hereinafter described in detail. Roll paper supply means, generally designated at 9, serves to feed and guide a continuous paper tape into the printing area, which is generally designated at 11. A pin carriage 13, having a plurality of vertical columns of five depressible pins each is slidably supported on a shaft and guided during its translation by the cooperation of at least one upright extended portion 17 of the pin carriage back plate with a transverse groove formed in a stationary support member 19. The pin carriage 13 is normally retained in an extreme rightmost position on the shaft 15 (away from the viewer as illustrated in FIG. 2), and is biased in an opposite leftward direction by a spring 20. The pin carriage is returned to its rightmost home position against the bias of the spring 20 following each listing operation of the machine. Mechanical escapement means are provided the pin carriage 13, such that the pin carriage will escape a one unit distance to the left, by means of the spring 20, upon each depression of a numeric key of the keyboard. Since pin carriage escapement and return means are well known in the calculator art, they are neither shown in the drawings nor made a part of the present invention.

A keyboard generally designated at 21 in FIGS. 1 and 2 is of conventional design and comprises a single set of numeric keys representing the values 0 through 9, and at least four operation control keys including a plus and minus motor bar, and a total and subtotal key. The ten numeric keys of the keyboard may be cooperably coupled by any well known means (not shown) to a single vertical array of pin depressors 23 that are slidably supported in a stationary support member 25 (as best shown in FIG- 2). In like manner, the operation control keys of the keyboard 21 may be cooperably coupled by any well known means (not shown) to the motor 3 and to clutch actuating means associated with the first and second drive shafts 5 and 7, the latter means being hereinafter described in detail.

An accumulator generally designated at 27 in FIG. 2 is comprised of a plurality of ordinally arranged transfer pinions 29, a plurality of carry wheels 31, a plurality of resettable gears 33, a plurality of read-out wheels 35, and a plurality of accumulator cam wheels 37 (as shown in FIGS. 12, 13 and 14A).

A printing element carrier, generally designated at 39, and comprising a single rotatable printing sector 41 having type characters 0 through 9 disposed along a portion of its periphery, is translatable along a shaft 43 and guided in its translation by a projecting L-shaped guide arm 45 riding in a second transverse groove formed in the stationary support member 19. The printing element carrier 39 is biased toward a home position at the rightmost extremity of the shaft 43 (away from the viewer as shown in FIG. 2), and is activated in a step-wise fashion from right to left by means of the first drive shaft 5 as described in a later section. As the printing element carrier 39 is activated from right to left during listing and accumulating operations, the printing sector 41 is differentially rotated to bring selected type characters into printing position, as determined by the forwardly positioned or depressed'pins in the various vertical columns of the prepositioned pin carriage 13. As the printing sector 41 isdifferentially rotated in each of the ordinal positions encompassed in its right to left translation, a single output pinion or actuator 47 thereof is rotated a corresponding distance in a counterclockwise direction. Although this counterclockwise rotation of the output'pinion 47 would have no effect on the accumulator during non-add listing operations, in the event such a function is desired, it is effective to transfer values corresponding to rotations of the printing sector into the associated sets of ordinally arranged pinions and gear wheels of the accumulator during accumulating operations, as hereinafter fully described.

During total and subtotal operations of the preferred embodiment of the invention, the second drive shaft 7 is rotated one complete revolution to permit a pair of accumulator slides associated with each ordinal set of pinions and gear wheels of the accumulator to sense the cam surfaces of their associated accumulator cam wheels 37, such accumulator slides being generally designated at 49 in FIG. 2. The rearmost extremity of one of each pair of accumulator slides 49 (as viewed in FIG. 2) is provided with four step-like limits which cooperate with one of the indexing slides of the printing element carrier 39 during total and subtotal operations, and the other of each pair of slides is provided with a single step-like limit which cooperates with the other of the indexing slides, such cooperation being similar in nature to the cooperation of the indexing slides with the forwardly advanced or depressed pins of the pin carriage 13 during listing and accumulating operations. Accordingly, upon depression of the total or subtotal key of the keyboard 21, the second drive shaft 7 is rotationally activated, as hereinafter described, to rearwardly position the accumulator slides 49, and the first drive shaft 5 is additionally rotationally activated to step-wise translate the printing element carrier 39 from right to left, as in a listing or accumulating operation, the printing sector 41 being differentially rotated in each ordinal position to bring selected type characters into printing position as determined by the step-like limits of the accumulator slides 49. It is to be noted, as in other well known ten key calculators, that the pin carriage 13 is retained in its inactive home position (rightmost position) during total and subtotal operations, thereby rendering the accumulator slides 49 solely operative to limit the pair of indexing slides of the carrier 39 during such operations, the amount printed by means of the printing sector 41 in each ordinal position thereby representing the amount that is read out of the accumulator cam wheels 37.

Totaling operations of the inventive low cost calculator, in addition to effecting the serial printing of the amount read from the accumulator cam wheels 37, also provide for the clearing or zeroizing of the various sets of accumulator pinions and gear wheels following the reading of the stored amount. The preferred embodiment of the low cost calculator provides a hereinafter described reset mechanism for this purpose, such mechanism being operatively associated with the accumulator reset gears 33 and with the second drive shaft 7, and responsive to the depression of the total key of the keyboard.

The read-out wheels 35 are each provided with a cylindrical rim (not shown in the drawings), such rim bearing the numerals 0 through 9 which are readable through a rectangular window 51 (shown in FIG. 1) in the case 53.

With reference to FIG. 2, also, a single elongated hammer generally indicated at 55 is disposed in a freely rotatable state on the shaft 43, and is comprised of a pair of spaced apart upright arms 57, a connecting print bar 59 extending across and beyond the width of the roll paper, and a pair of cam follower extensions 61 connected to the upright arms 57. An inked ribbon generally designated at 63 in FIG. 1 is feedably supported in conventional fashion and is guided by a pair of posts 65 between the print bar 59 and the printing sector 41 of the printing element carrier 39. Paper feed and guide means generally designated at 67 in FIG. 2 is effective to feed the paper between the upright arms 57 of the hammer 55 and between the inked ribbon and the print bar 59.

The above identified parts are for the most part shown in the plan view of FIG. 1, wherein the operating sections of the low cost calculator are illustrated in assembled state within the machine case 53 and supported by a base 69. A pair of frame members 71 and 73 fixed to the base 69 provide support for the first and second drive shafts and 7, shaft along which the pin carriage 13 translates, support member 19, the horizontal grooves of which provide guiding support for both the pin carriage l3 and the printing element carrier 39, and for shaft 43 along which the printing element carrier 39 translates. The rightmost frame member 71 is more durable in structure than the leftmost member 73, inasmuch as it provides operational support for a square shaft 75 associated with the printing sector 41, such square shaft being provided with activating means generally designated at 77. This square shaft activating means, as hereinafter described, is effective to bi-directionally rotate the squareshaft 75 and to thereby advanceably and retumably activate the printing sector 41 of the printing element carrier 39. Also shown in FIG. 1 are a pair of spaced apart accumulator frame members 79 by means of which the various pinion and gear wheel supporting shafts of the accumulator are journaled. The printing element carrier 39 is supported by and contained within a pair of spaced apart and inter-connected frame members 81 which are translatable along the square shaft 75 and the shaft 43.

It can also be seen from FIG. 1 that the continuously rotating motor 3 is connected by means of a belt 83 to a pulley 85 axially disposed of the first drive shaft 5. Integral with the pulley 85 is a gear wheel 87 which is engageably associated with a gear wheel 89 axially disposed of the second drive shaft 7. Adjacent the gear wheel 87 and associated with the first drive shaft 5, is a first spring clutch 91, and adjacent the gear wheel 89 and associated with the second drive shaft 7 is a second spring clutch 93. Each of these spring clutches is of the well known torsion spring type, wherein an internal spring is held expanded by exterior abutment means to thereby effect uncoupling of its associated drive shaft from its associated rotating gear wheel, and wherein displacement of the abutment means enables contraction of the spring to thereby effect coupling of the drive shaft with the associated rotating gear wheel.

It can also be seen from FIG. 1 that the first drive shaft 5 is comprised of a pair of spaced-apart hammer driving cams 95, which cooperate with the cam follower extensions 61 of the hammer 55, and add-subtract cam 97, a cam 99 associated with the square shaft activating means 77, and a drive screw 101 effective for translatably activating the printing element carrier 39. As can also be seen from FIG. 1, the second drive shaft 7 is comprised of a total-subtotal cam 103 for activating the accumulator slides 49, and a fixed pulley 105 which is belt connected to a smaller pulley 107 associated with the shaft providing rotational support for the reset gears 33 and with mechanism for resetting said gears.

The construction of the preferred embodiment of the printing element carrier 39, in so far as its framing and supporting structure is concerned, can best be described with reference to FIGS. 3, 5 and 6, in which the previously described L-shaped guide arm 45 and frame members 81 are also shown. The frame members 81 comprise an extended portion 8lishown in FIGS. 5 and 6, for supporting the output pinion 47 (shown in FIG. 7), and are staked together by means of first, second, and third connecting guide plates 109, 111, and 113, respectively, each of the connecting guide plates being provided with appropriately dimensioned slots for translatably guiding the previously mentioned pair of indexing slides. These indexing slides are herein designated as a rightmost indexing slide and a leftmost slide 117. The first connecting .plate 109 integrally comprises the pair of previously mentioned L- shaped guide anns 45 which ride within a forward groove of the stationary support member 19. The slot of the first connecting plate 109, for slidably accommodating the indexing slide 115, is held to such depth that a forwardly extending projection 119 of the slide will limit on the underside thereof when the slide is not otherwise limited during its upward excursion, as will be described in greater detail hereinafter.

The second connecting plate 111 is L-shaped in formation, as illustrated in FIGS. 5 and 6, the vertical portion thereof being provided with a continuous slot for receivably guiding a forwardly extending projection 121 of the indexing slide 1.17. The slot fonned in the horizontal portion of the connecting plate 111 is held to such dimension that the projection 121 will limit on the underside of the horizontal portion of the plate 111 when the slide 117 is not otherwise limited during its upward excursion. The third connecting plate 113 is substantially of U-shaped formation, a rearward extension thereof serving to anchor one end of a hereinafter described spring 123.

Each of the frame members 81 of the printing element carrier 39 is provided with an upper and lower aperture for accommodating an upper collared sleeve 125 and a lower collared sleeve 127. Each of the upper collared sleeves 125 is provided with a central aperture for receiving a hereinafter described bushing, and each of the lower collared sleeves 127 is provided with a cylindrical aperture that slidably accommodates the shaft 43. Rockably disposed on corresponding steps of the collared sleeves 127 is a channel-shaped screw engaging member 129, the side walls thereof outwardly stradling the frame-members 81. A depending projection 131 of this channel-shaped member is provided with a screw engaging stud 133 cooperably disposed relative to the drive screw 101, and a rearwardly extending projection thereof, opposite the depending projection 131, serves to anchor the lower end of the spring 123. The channel-shaped member 129 is accordingly afforded a normal bias effective to hold the screw engaging stud 133 disengaged from the drive screw 101. The channel-shaped member 129 is also provided with a rearwardly extending projection 139 which is blockably associated with a biased latch member 141 carried by the rightmost frame member 81. The latch member 141 is pivotally connected to an offset projection 143 of the frame member 81, and is biased in a counterclockwise direction thereon (as viewed in FIGS. 3 and 4) by a spring 145 which is compressibly disposed between the frame member and an upright extension of the latch member 141, the spring being effective to bias the latch member into latching relationship with the projection 139. The latch member 141 is also provided with a first and second offset knock-off projection 147 and 309, the latter being shown in FIGS. and 13.

In addition to the forwardly extending projections 119 and 121, the indexing slides 115 and 117, respectively, are provided with offset rearwardly extending projections 135 and 137, the offsetting of such projections serving to locate the extremities thereof in a common vertical plane, such plane corresponding to the planes of the vertical columns of pins in the pin carriage 13 during the right to left excursion of the printing element carrier 39 during listing and accumulating operations. The indexing slides 115 and 117 are also each provided with a plurality of teeth (FIGS. 5 and 6) that are arranged on the upper forward edge thereof, such teeth being engaged with a gear wheel 149 and a geared sector 151, respectively. The gear wheel 149 associated with the indexing slide 115 is provided with an integral gear wheel 153 (shown in FIG. 7), and the geared sector 151 associated with the indexing slide 117 is provided with an integral geared sector 155. The integral gears 149-153 and the integral geared sectors 151-155 are each snugly fitted on a continuous bushing 157, best shown in FIG. 18, which is contained within the collared sleeves 125, the bushing being provided with a square central aperture which slidably cooperates with the square shaft 75. The fit of the bushing 157 within the central apertures of the integral gears 149-153 and the integral geared sectors 151-155 is such that the shaft 75 may be rotated when either the gears 149-153 or the geared sectors 151-155 are blockably prevented from rotating, and prevented from rotating when both the gears 149-153 and the geared sectors lSl-lSS are blockably prevented from rotating.

As best illustrated in FIGS. 7, 8 and 9, the printing sector 41, in addition to its previously described typebearing periphery, it also provided with a toothed portion 159 which is disposed opposite the type characters 0 through 9. Contained also within the printing sector 41, and in particular within that portion of the sector that supports the type-bearing periphery, are a pair of intermeshed differential gears 161 and 163 which are rotatably mounted on a pair of mounting posts 165. It can also be seen from FIGS. 7 and 8 that the previously described output pinion 47 also comprises an integral gear wheel 167 which is cooperably engaged with the toothed portion 159 of the printing sector 41, the integral output pinion 47-167 being rotatably mounted on a shaft 169 connecting the frame members 81 of the printing element carrier 39.

It will be understood from the abovedescribed structure of the indexing slides 115 and 117 and the gearing of the printing element carrier 39, that a clockwise rotation of the square shaft (as viewed in FIG. 8) will be effective to differentially advance the printing sector 41 to bring selected type characters into printing position, such differential advancement being accompanied by an upward activation of the indexing slides and 117 according to the distance these individual slides are permitted to be raised.

As will be fully described in a later section, the pin carriage 13 is called into play to differentially restrict the upward activation of the indexing slides 115 and 117 during listing and accumulating operations, whereas the accumulator slides 49 are called into play to effect such restriction during subtotaling and totaling operations. It will be noted in the discourse relating to such operations, that the indexing slide 117 (FIG. 6) is permitted a maximum upward travel of one unit,

whereupon its forwardly extending projection 121 limits on the underside of the second connecting plate 11 1 of the printing element carrier 39, and the indexing slide 115 (FIG. 5) is permitted a maximum upward travel of four units, whereupon its forwardly extending projection 119 limits against the underside of the first connecting plate 109.

The differential advancement of the printing sector 41, as effected by the hereinafter described clockwise rotation of the square shaft 75 and the previously mentioned cooperation of its differential gearing, may accordingly be described both with and without a one unit upward advancement of the indexing slide 117, with reference to FIGS. 5, 6, 7, 8 and 9. When the latter indexing slide is blocked against such upward activation, the clockwise rotation of the shaft 75 causes the gears 149-153 (FIG. 7) to rotate in a corresponding direction, the gear wheel 153 thereby attempting to rotate the differential gear 161 (FIGS. 8 and 9) in a counterclockwise direction on its mounting post 165. Since the geared sectors 151-155 and the differential gear 163 are prevented from rotating by the blocked slide 117, however, thereby preventing the intermeshed differential gear 161 from rotating, rotation of the gear wheels 149-153 accordingly serves to advanceably rotate the printing sector 41 itself, until the indexing slide 115 is limited by a pin of the pin carriage 13, a step-like limit of the accumulator slide 49, or by the underside of the first connecting plate 109. When the indexing slide 117 is permitted a one unit upward advancement, on the other hand, clockwise rotation of the square shaft 75 causes the geared sectors 151-155 to rotate a corresponding one unit clockwise distance, the geared sector 155 serving to rotate the differential gear 163 a corresponding distance in a counterclockwise direction, the interrneshed differential gear 161 being thereby rotated a one unit distance in a clockwise direction. The resulting clockwise rotation of the gear wheels 149-153 accordingly advances the printing sector 41 an additional unit distance by the time the projection 119 of the indexing slide 115 is brought into contact with one of the above described variable limits.

The differential gearing contained within the printing sector 41 is also effective to produce a one unit advaricement of the printing sector 41 when the indexing slide 115 is blocked against upward activation and the slide 117 is not so blocked, such advancement being effective to position the 1 type character in printing position. In such instance clockwise rotation of the square shaft 75 attempts to rotate the geared sectors 151-155 in a clockwise direction and the differential gear 163 in a counterclockwise direction. Since the gear wheels 149-153 and the differential gear 161 are prevented from rotating by the blocked indexing slide 115, however, rotation of the geared sector 151-155 accordingly serves to advanceably rotate the printing sector 41 itself, until the indexing slide 117 is limited by the underside of the second connecting plate 111 or by the step-like limit of the accumulator slide 49.

The square shaft activating means generally designated at 77 in FIG. 1 can best be described with reference to FIGS. 7 and 11, wherein an extension of the square shaft 75 is shown to be joumaled in a bearing 171 mounted on the frame member 71, and shown also to be provided with a fixed gear 173. A toothed sector arm 175 is pivotally mounted on the frame member 71 by means of a short shaft 177, the toothed surface thereof being cooperably engaged with the gear 173 and the lowermost extremity thereof being provided with a rotatable cam following roller 179 disposed in cooperating relationship with the cam 99 of the first drive shaft 5. As shown in FIG. 7, the toothed sector arm 175 is retained in cooperating relationship with the cam 99 by means of a spring 181 connected to an anchor stud 183 fixed to the sector arm 175 and to an anchor stud fixed to the frame member 71 (not shown). The contour of the cam 99 is such that the raised portion thereof effectively holds the toothed sector arm 175 in a full counterclockwise rocked position on the shaft 177 (as viewed from the right in FIG. 11), and against the full bias of the spring 181, when the machine is at rest. Upon depression of an operation control key of the keyboard, the first drive shaft is rotated in a counterclockwise direction (as viewed from the right in FIG. 11), the raised portion of the cam 99 being accordingly withdrawn from the cam following roller 179 of the toothed sector arm 175. The sector arm 175 is rotated by the spring 181 in a clockwise direction and the toothed portion of the sector arm rotates the gear 173 and the square shaft 75 in a counterclockwise direction (clockwise direction as viewed in FIG. 8). At the 270 point in each revolution of the first drive shaft 5, the raised portion of the cam 99 begins to restorably rotate the sector arm 175 against the bias of the spring 181, thereby rotating the gear 173 and the square shaft 75 in a clockwise direction (counterclockwise direction as viewed in FIG. 8) and restoring the printing sector 41 from its differentially advanced position to its normal home position, such restoration being accomplished by the gear wheels 149-153, the geared sectors 151-155 and the differential gears 161 and 163, as described with reference to FIGS. 8 and 9.

As was indicated with reference to FIGS. 1 and 2, the pin carriage 13 is step-wise translatable from right to left along the shaft 15 by well known escapement means upon depression of each numeric key of the keyboard 21, such key depression and right to left escapement serving to advance or to depress one or more pins in a vertical column of the pin carriage, and to align the vertical columns of pins with corresponding orders of the accumulator gear wheels. Whereas known pin carriages normally provide eight or nine pins in each vertical column, each column of the present invention is provided with but five pins to represent the decimal values one through nine, as can best be described with reference to FIGS. 10 and 12. Although six pins are shown in vertical array, the lowermost pin may be provided as a facility for entering two or more 0s, and is accordingly not made a part of the present invention. The remaining pins in each vertical column, namely pins 187, 189, 191, 193 and are employed for entering the decimal values 0 through 9. Pin 187 may be defined as the 0-1 pin associated with the indexing slide 117, pin 189 as the 0 pin associated with the indexing slide 1 15, pin 191 as the 2 pin, 193 as the 4 pin, and 195 as the 6 pin. Accordingly the preferred embodiment of the invention provides a keyboard arrangement whereby depression of the 0 key activates the pins 187 and 189 in a given vertical column, depression of the 1 key activates pin 189 only, depression of the 2 key activates the pins 187 and 191, depression of the 3 key activates pin 191 only, depression of the 4 key activates pins 187 and 193, depression of the 5 key activates pin 193 only, depression of the 6 key activates pins 187 and 195, depression of the 7 key activates pin 195 only, depression of the 8 key activates pin 187 only, and depression of the 9 key will not activate any of the pins of the pin carriage. In other words, to enter a 0 in a given order, the pins 187 and 189 being activated, projection 135. of the indexing slide 115 is blocked by the pin 189, and the projection 137 of the indexing slide 1 17 is blocked by the pin 187, minimal upward activation of the indexing slide 117 being permitted in order to advance the zero type of the printing sector 41 to printing position. This minimal advancement of the printing sector is known as visible printing in the well known printing calculator art. To enter a 1 in a given order, the pin 189 only being activated, the indexing slide 115 is blocked by the pin 189 and the indexing slide 117 is permitted a one unit upward movement to limit against the underside of the second connecting plate 111. To enter a 2 in a'given order, the pins 187 and 191 being activated, the indexing slide 1 17 is blocked by the pin 187 and the slide 1 15 is permitted two units of upward movement to limit against the pin 191. To enter a 3, the pin 191 only being activated, the indexing slide 115 is permitted a two unit upward movement to limit against the pin 191, and the slide 117 is permitted a one unit upward movement to limit against the plate 111, the combined upward travel of the two slides advancing the printing sector 41 to locate the 3 type character in printing position. To enter a 4 in a given order, the pins 187 and 193 being activated, the indexing slide 117 is blocked by the pin 187, and the slide 115 is permitted a four unit upward movement to limit against the pin 193. To enter a 5, the

pin 193 only being activated, the slide 115 is permitted being activated, the indexing slide 117 is blocked bythe pin 187, and the slide 1 15 is permitted a six unit upward movement to limit against the pin 195. To enter a 7, the pin 195 only being activated, the slide 117 is permitted a one unit upward movement to limit against the plate 111, and the slide 115 is permitted a six unit upward movement to limit against the pin 195, the combined upward travel of the slides serving to locate the 7 type character in printing position. To enter an 8, the pin 187 only being activated, the slide 117 is blocked by the pin 187, and the slide 115 is permitted an eight unit upward movement to limit against the first connecting plate 109. To enter a 9, none of the pins being activated, the slide 117 is permitted a one unit upward movement to limit against the plate 111, and the slide 115 is permitted an eight unit upward movement to limit against the plate 109, the combined upward travel of the two slides being effective'to locate the 9 type character in printing position.

With reference to FIGS. 10, 11 and 12, the previously identified pinions and gear wheels of the accumulator 27 are rotatably supported by a plurality of shafts extending between the accumulator frame members 79. The relationship of these shafts is best illustrated in FIG. 12 wherein a shaft 197 is shown in supporting relationship with the transfer pinions 29, a shaft 199 is shown to support the carry wheels 31, a shaft 201 is shown to support the reset gears 33, a shaft 203 is shown to support the read-out wheels 35, and a shaft 205 is shown to support the accumulator cam wheels 37. The shafts 197, 199, 203 and 205 are rigidly connected to the frame members 79, whereas the shaft 201 is rotatably journaled within the frame members 79, the rotation of this latter shaft being described in detail in connection with a totaling or clearing operation of the calculator. It will be observed that the shafts 197 and 199 are supported by a cradle 207 forming a detail of the accumulator frame assembly, such cradle being comprised of a pair of spaced apart and interconnected pivot arms 209 which are pivotally connected to the frame members 79 by a pair of pins 211. The pivot pins 211 are so arranged on the frame members 79 that the rocking action of the cradle 207, to effectively engage and disengage the transfer pinions 29 with and from the output pinion 47, isminimized, the placement of the pins being at the interstice of the pitch circles of the carry wheels 31 and the reset gears 33.

The preferred embodiment of the inventive low cost calculator provides transfer pinions 29 having eight teeth each, and utilizes two teeth on each of the remaining gear wheels and pinions of the accumulator to represent a single digit value. The carrying wheels 31, readout wheels 35 and accumulator cam wheels 37 are accordingly each provided with 20 teeth, and the reset gears 33 are each provided with forty teeth to accommodate the requirements of accumulator clearing, as hereinafter described. It can be seen from FIG. A that each of the transfer pinions 29 is of wider dimension than the other gears and gear wheels of the accumulator, and that each of the carry wheels 31 is provided with two wide teeth 213 that are cooperably engageable with the adjacent higher order transfer pinion 29. It can thus be seen that as the printing element carrier 39 is sequentially translated from right to left during accumulating operations, the single output pinion 47 thereof will transfer the serially printed amounts into corresponding orders of the accumulator by means of the transfer pinions 29, and that when an exceed capacity condition develops in a given order of the accumulator, the corresponding carry wheel 31 will transfer a carry into the adjacent higher order accumulating wheel by means of the wide teeth 213 engaging and advancing the adjacent higher order transfer pinion 29 an equivalent one unit distance.

As hereinafter described in greater detail, the transfer pinions 29 are engageable with the single output pinion 47 of the printing element carrier 39, by the pivotal action of the cradle 207, at the inception of either the upward or downward movement of the in dexing slides and 117, or, in other words, at the inception either of the advanceable or return activation of the printing sector 41. The transfer pinions 29 are accordingly rotated in either a clockwise or counterclockwise direction, the clockwise rotation thereof (as viewed in FIG. 12) representing an additive accumulating operation, and the counterclockwise rotation thereof representing a subtractive accumulation. In view of the gear-train relationship of the several pinions and gear wheels of the accumulator, an additive clockwise rotation of the transfer pinions 29 results in a clockwise rotation of the reset gears 33 and a counterclockwise .rotation of the accumulator cam wheels 37. During a subtractive accumulation, the reset gears 33 are rotated in a counterclockwise direction, and the accumulator cam wheels 37 in a clockwise direction. It is to be noted from FIGS. 13 and 14A that each of the accumulator cam wheels 37 is sandwiched between a pair of differently shaped cam segments 215 and 217, each cam segment 215 providing positioning control of an associated O-l accumulator slide 219 during subtotal and total operations, and each cam segment 217 providing positioning control of an associated totalsubtotal accumulator slide 221. Each of the accumulator slides 219 and 221, which were previously referred to generally as 49, is provided with an upper camabutting projection 223, and with a rearmost extremity that is effective for blockably limiting the upward travel of the indexing slides 115 or 117 of the printing element carrier 39 during totaling and subtotaling operations, in like manner to the pins of the pin carriage during listing and accumulating operations. The rearmost extremity of each of the total-subtotal slides 221 is provided with four step-like limits which correspond in function to the pins 189, 191, 193 and 195 of the pin carriage, such function being the blocking of the indexing slide 115. The rearmost extremity of each of the 0-1 accumulator slides 219 is provided with a single step-like limit which corresponds in function to the pins 187 of the pin carriage, such function being the blocking of the indexing slide 117.

As hereinafter explained in connection with the operation of the low cost calculator, the accumulator slides 219 and 221 are activated rearwardly (to the left as viewed in FIGS. 12 and 13) during totaling and subtotaling operations, the projections 223 coming to rest against the cam surfaces of their associated cam segments of the accumulator cam wheels 37. The rearmost extremities of the accumulator slides 219 and 221 accordingly serve to sequentially control the upward movement of the indexing slides 115 and 117 and the advanceable activation of the printing sector 41. The values that are stored in the accumulator are correspondingly read and printed sequentially from right to left as in listing and accumulating operations. The total-subtotal slides 221 are slidably supported by guide combs 224,225, 227 and 229, each of which is rigidly connected to the accumulator frame members 79, and the -1 slides 219 are slidably supported by the guide comb 229 and a guide comb 231, as best illustrated in FIG. 13. The slides 221 are biased rearwardly (to the left as viewed in FIG. 13) by springs 233 connected to a spring anchor thereof and to a spring anchor strip 237 supported by the frame members 79. The slides 219 are biased rearwardly by springs 235 connected to a spring anchor thereof and to the guide comb 231. Both sets of accumulator slides are held forwardly when the machine is at rest, and during listing and accumulating operations, by a cam follower lever 239 and the raised portion of the total-subtotal cam 103, and are released to the bias of their associated springs at a predetermined point in totaling and subtotaling operations as the cam 103 is rotated in a counterclockwise direction. In FIG. 14A, identification is provided as to the surfaces of the cam segments 215 and 217 that are contacted by the accumulator slides 219 and 221 when the values 0 through 9 are stored in an accumulator cam wheel. When the digit value 0 is stored in an accumulator cam wheel, the corresponding slides 215 and 219 are permitted, during a subtotal and total operation, to assume their extreme rearrnost positions to thereby block the indexing slides 115 and 117 of the printing element carrier against upward travel, a 0 being accordingly printed by the printing sector 41. When a digit value of l is stored in an accumulator-cam wheel, the associated slide 221 is permitted to assume its extreme rearmost position to thereby prevent upward travel of the indexing slide 115, and the slide 219 is held in its forward position to thereby permit a full unit of travel of the indexing slide 117 as defined by the connecting plate 111. When a digit value of 2 is stored in an accumulating wheel, the associated slide 221 is positioned .to blockably limit the indexing slide 115 to one degree of upward travel, and the slide 219 is so positioned to block the indexing slide 117- against upward movement, the combination serving to locate the 2 type character in printing position. When a digit value of 3 is stored in a cam wheel, the associated slide 221 is positioned to limit the indexing slide 115 to one degree of upward travel, and the slide 219 is so positioned as to permit a full unit of upward travel of the indexing slide 117, the combination serving to locate the 3 type character in printing position. In like manner, when the digit values 4 and 5 are stored, the associated slide 221 is positioned to blockably limit the indexing slide 115 to 2 of upward travel, and the slide 219 is positioned to either prevent (in the case of a 4) or to allow (in the case of a 5) a one unit upward travel of the indexing slide 117, the combination serving to position either the 4 or 5 type character in printing position. When a digit value of 6 or 7 is stored, the slide 221 is positioned to blockably limit the indexing slide 115 to three degrees of upward travel, and the slide 219 is positioned to either prevent (in the case of a 6) or to allow (in the case of a 7) a one unit upward travel of the indexing slide 1 17, the combination serving to position the 6 or 7 type character in printing position. When the digit values 8 or 9 are stored, the slide 221 is positioned forwardly of the indexing slide to permit 4 of upward travel, to be thereby limited by the under side of the connecting plate 109, and the slide 219 is positioned to either prevent (in the case of an 8) or to allow (in the case of a 9) a one unit upward travel of the indexing slide 1 17, the combination serving to position the 8 or 9 type character in printing position.

It will be observed from FIG. 14A that those surfaces of the cam segments 215 that correspond to the digit values 2, 4, 6 and 8, permit a lesser degree of rearward movement of the slides 219 than does the surface of the cams corresponding to the digit value 0, although each of these surfaces serves to block the indexing slide 117 against upward activation. The surfaces of the cam seg ments 215 corresponding to the digit value 0 additionally serve to establish a farther rearward position for the slides 219, such farther rearward position being effective for terminating the right to left excursion of the printing element carrier 39 during total and subtotal operations, as will be explained in greater detail hereinafter.

Each of the 0-1 accumulator slides 219 is associated with a zero suppression lever 243 pivotally mounted on a shaft 245 connected to the accumulator frame members 79, as shown in FIG. 13. A guide comb 247 supported by the frame members 79 and the guide comb 229 provide rockable support for these zero suppression levers, and each is provided with a spring 249 connected to an. anchor projection thereof and to any suitable anchor attached to the frame members of the accumulator. Each of the zero suppression levers 243 is provided with a leftwardly directed offset projection on its uppermost extremity (as viewed from the right in FIG. 13), and with a rightwardly directed offset projection on its lowermost extremity, the latter projection of each lever being cooperable with a depending projection 251 formed on the adjacent lower order slide 219. The zero suppression levers 243 are normally biased in a clockwise direction on the shaft 245 by the springs 249, with their leftwardly directed projections engageably aligned with their adjacent higher order slides 219, and their rightwardly directed projections engageably aligned with the depending projections 251 of their adjacent lower order slides 219. During total or subtotal operations, the highest order slide 219 that is held displaced from the zero surface of its cam segment 215 by the presence of a value of at least one in its associated accumulator cam wheel 37, will enable its associated zero suppression lever 243 to remain in its clockwise rocked position as motivated by its spring 249, the lower order slides 219 being blockably withheld from contacting the zero surfaces of their associated cam segments by the cooperation of the rightwardly and leftwardly directed offset projections thereof, to thereby prevent any of the lower order slides 219 having Os stored therein from terminating the right to left excursion of the printing element carrier 39, such termination being described hereinafter in connection with totaling and subtotaling operations. The arrangement of the offset projections of the zero suppression levers 243 is such that those slides 219 disposed to the left of the highest order in which a value of one or more is stored will be permitted to move into contact with the zero surfaces of their respective cam segments 215, the slide 219 leftwardly adjacent the 

1. In a printing calculator having a ten-key keyboard, roll paper supply means, a platen, actuating means, and a plurality of ordinally arranged accumulator wheels, the combination comprising: a. a pin carriage having a predetermined number of keyboard responsive depressible pins, said pin carriage being also escapeably responsive to said keyboard and returnably responsive to said actuating means, b. a single print hammer associated with said actuating means, c. a plurality of sensing slides associated with said plurality of accumulator wheels, d. a single printing sector cooperable with said pin carriage and with said sensing slides of said accumulator wheels for selectively positioning the type characters thereof in printing position relative to said print hammer, and e. a single accumulator actuator associated with said single printing sector and cooperable with said plurality of accumulator wheels for accumulating therein values corresponding to said selectively positioned type characters.
 2. The printing calculator as defined in claim 1 wherein said single printing sector and said single accumulator actuator are combined in a translatable printing element carrier, said carrier being translatable in a first direction by said actuating means and in a second direction by biasing means, said first direction translation serving to provide serial advancement of said carrier from the least to the most significant orders of said accumulator wheels, and said second direction translation serving to return said carrier to its home position.
 3. The printing calculator defined in claim 2 wherein said printing element carrier is translatable along a first supporting shaft and a square shaft associated with said single printing sector.
 4. The printing calculator defined in claim 3 wherein said single printing sector of said printing element carrier is comprised of a type-character-bearing portion and a toothed portion, and is provided with a central aperture slidably associated with said square shaft along which said printing element carrier translates, said type-character-bearing portion bearing the characters 0 through
 9. 5. The printing calculator defined in claim 4 wherein said printing element carrier additionally comprises: a. a pair of interconnected supporting frame members having upper and lower apertures for slidably accommodating said square shaft and said first supporting shaft, b. first, second, and third connecting plates effectively connecting said pair of supporting frame members of said printing element carrier, c. a pair of indexing slides cooperably associated with said depressible pins of said pin carriage and with said sensing slides of said accumulator wheels, said indexing slides being translatably and guidaBly supported by cut-outs formed in said first, second and third connecting plates, d. differential gearing coupling said pair of indexing slides with said single printing sector, e. a channel-shaped engaging member cooperably associated with said actuating means, and f. a biased latch member associated with said channel-shaped member and effective for retaining said latter member in cooperating relationship with said actuating means.
 6. The printing calculator defined in claim 5 wherein: a. said printing element carrier additionally comprises a second supporting shaft connecting said pair of supporting frame members thereof, and b. said single accumulator actuator is a gear wheel rotatably supported by said second supporting shaft, said gear wheel having an integral gear wheel member engageably disposed relative to said toothed portion of said single printing sector.
 7. The printing calculator defined in claim 5 wherein said single print hammer comprises: a. a pair of spaced apart upright arms rotatable on said first supporting shaft, said apart spacing being greater than the dimensional width of the roll paper carrier by said roll paper supply means, b. a pair of cam follower extensions disposed on the lowermost extremities of said upright arms, said extensions being cooperably associated with said actuating means, and c. a print bar connecting the uppermost extremities of said upright arms, said print bar defining a printing position relative to said platen.
 8. The printing calculator defined in claim 7 wherein said actuating means thereof comprises: a. a constant running motor operatively associated with said keyboard, b. a first drive shaft cooperably associated with said printing element carrier, said single print hammer, said square shaft, and said accumulator wheels, c. first drive shaft actuating means effective for coupling said first drive shaft with said motor, d. a second drive shaft cooperably associated with said accumulator wheels and with said first drive shaft, and e. second drive shaft actuating means effective for coupling said second drive shaft with said motor.
 9. The printing calculator defined in claim 8 wherein said first drive shaft of said actuating means comprises: a. a drive screw extending a predetermined distance along the length thereof, said drive screw being provided with a continuous thread, adjacent pairs of threads thereof being disposed in a perpendicular relationship to the axis of said first drive shaft for approximately 270 circumferential degrees, and angularly disposed relative to said axis for approximately 90 circumferential degrees, b. a first cam cooperably associated with said square shaft, c. a second cam cooperably associated with said accumulator wheels, and d. a pair of spaced-apart cams cooperably associated with said pair of cam follower extensions of said single print hammer.
 10. The printing calculator defined in claim 9 wherein said channel-shaped engaging member of said printing element carrier is provided with a screw engaging stud, said stud being engageably receivable between adjacent pairs of threads of said drive screw of said first drive shaft in response to said first drive shaft actuating means, to thereby effectuate the translation of said printing element carrier by said first drive shaft, said translation being in a first direction which is characterized by an ascending order of significance.
 11. The printing calculator defined in claim 10 wherein said first drive shaft actuating means comprises: a. a first spring clutch associated with said constantly running motor and with said first drive shaft, and b. a first clutch engaging member responsive to said keyboard and effective for contractionally releasing said first spring clutch and for rotating said channel-shaped member of said printing element carrier such that said screw engaging stud is engaged with said drive screw of said First drive shaft, said contractional release of said first spring clutch and said engagement of said stud with said drive screw being effective to couple said first drive shaft with said constant running motor and to translate said carrier in said first direction, said engagement of said stud with said drive screw being effective also to release said latch member of said printing element carrier to its said bias such that said stud is retained in engaged relationship with said drive screw throughout said first direction translation of said carrier.
 12. The printing calculator defined in claim 9 wherein said plurality of ordinally arranged accumulator wheels are rotatably supported by a pair of accumulator frame members, and wherein each accumulating order is comprised of: a. a transfer pinion cooperably engageable with said single accumulator actuator of said printing element carrier, b. a carry wheel disposed in engaged relationship with its associated transfer pinion, each carry wheel being provided with at least one wide tooth cooperably disposed relative to the adjacent higher order transfer pinion, c. a reset gear disposed in engaged relationship with its associated carry wheel, d. an accumulator cam wheel disposed in engaged relationship with its associated reset gear, and e. a read-out wheel comprising numeric indicia arranged on a cylindrical rim thereof, each read-out wheel being disposed in engaged relationship with its associated reset gear.
 13. The printing calculator defined in claim 12 wherein said square shaft along which said printing element carrier translates is provided with square shaft activating means cooperably associated with said first cam of said first drive shaft, said activating means being effective to alternately raise and lower said pair of indexing slides of said printing element carrier during each revolution of said first drive shaft as said carrier is translated in said first direction by said drive screw, said raising of said indexing slides serving to advanceably activate said printing sector to bring selected type characters into printing position, and said lower of said indexing slides being effective to restorably activate said printing sector to return said selected type characters to their normal home position.
 14. The printing calculator defined in claim 13 wherein said square shaft activating means comprises: a. a gear fixed to a shank portion of said square shaft, said shank portion being journaled in a frame member of said calculator, b. a pivotally mounted toothed sector arm having a cam following roller mounted on one extremity thereof, and having also a toothed portion disposed on its opposite extremity in cooperating relationship with said gear fixed to said square shaft, and c. a first spring connected to said sector arm and to a frame member of said calculator, said first spring being effective to differentially rotate said square shaft and said printing sector in a type-character-advancing direction upon the releaseable withdrawal of a raised portion of said first cam during each revolution of said first drive shaft, said raised portion of said first cam in cooperation with said cam following roller and said toothed sector arm being effective to rotate said square shaft and said printing sector in a type-character-restoring direction, the differential advanceable and restorable rotation of said printing sector being accompanied by a corresponding upward and downward travel of said indexing slides of said printing element carrier as motivated by said differential gearing thereof.
 15. The printing calculator defined in claim 14 wherein said pin carriage is provided with five keyboard-responsive depressible pins arranged in each vertical column thereof, a first of said pins when in its depressed state serving to restrain a first of said pair of indexing slides against any upward travel, a second, third, and fourth of said pins, when separately disposed in their depreSsed states, serving to limit said first indexing slide to one, two and three units of upward travel, respectively, and a fifth of said pins when in its depressed stage, serving to restrain a second of said pair of indexing slides against any appreciable upward travel, such restraining influence of said depressed pins occuring during said differential rotation of said square shaft and said printing sector in said type-character-advancing direction.
 16. The printing calculator defined in claim 15 wherein: a. the combined restraining influence of depressed first and fifth pins on said first and second indexing slides is effective to permit a minimum advancing rotation of said square shaft and said printing sector, said minimum advancement serving to locate the 0 type character in printing position, b. the separate restraining influence of a depressed first pin on said first indexing slide is effective to permit a one unit advancement of the printing sector, to locate the 1 type character in printing position, c. the combined restraining influence of depressed second and fifth pins of said first and second indexing slides is effective to permit a two unit advancement of the printing sector, to locate the 2 type character in printing position, d. the separate restraining influence of a depressed second pin on said first indexing slide is effective to permit a three unit advancement of the printing sector, to locate the 3 type character in printing position, e. the combined restraining influence of depressed third and fifth pins on said first and second indexing slides is effective to permit a four unit advancement of the printing sector, to locate the 4 type character in printing position, f. the separate restraining influence of a depressed third pin on said first indexing slide is effective to permit a five unit advancement to the printing sector, to locate the 5 type character in printing position, g. the combined restraining influence of depressed fourth and fifth pins on said first and second indexing slides is effective to permit a six unit advancement of the printing sector, to locate the 6 type character in printing position, h. the separate restraining influence of a depressed fourth pin on said first indexing slide is effective to permit a seven unit advancement of the printing sector, to locate the 7 type character in printing position, i. the separate restraining influence of a depressed fifth pin on said second indexing slide is effective to permit an eight unit advancement of the printing sector, to locate the 8 type character in printing position, and j. the absence of any restraint imposed on the pair of indexing slides, by reason of the absence of depressed pins in a given column of the pin carriage, is effective to permit a full predetermined upward travel of the first and second indexing slides, to locate the 9 type character in printing position.
 17. The printing calculator defined in claim 13 wherein said accumulator wheels are provided with accumulator activating means effective for engaging and disengaging said transfer pinions with and from said single accumulator actuator of said printing element carrier, said accumulator activating means being cooperable with said second cam of said first drive shaft to effectuate additive and subtractive accumulations of amounts differentially selected by said square shaft activating means as influenced by said depressible pins of said pin carriage.
 18. The printing calculator defined in claim 17 wherein said accumulator activating means comprises: a. a pair of arcuate grooves formed in opposite side surfaces of said second cam of said first drive shaft, b. a pivotally and translatably mounted first lever responsively associated with said keyboard, said lever being provided with a bifurcated portion effectively straddling said second cam, c. a pair of cam follower rollers interiorLy mounted on said bifurcated portion of said first lever in cooperating relationship with said pair of arcuate grooves, and d. a cradle pivotally mounted on said pair of accumulator frame members and resiliently coupled to said first lever, said cradle providing rockable support for said transfer pinions and said carry wheels, a first of said arcuate grooves when cooperably engaged by its associated roller being effective to rockably engage said transfer pinions with said accumulator actuator during the differential upward travel of said pair of indexing slides of said printing element carrier, and a second of said arcuate grooves being effective to rockably engage said transfer pinions with said accumulator actuator during the differential downward restoring travel of said pair of indexing slides.
 19. The printing calculator defined in claim 12 wherein said second drive shaft of said actuating means comprises: a. a third cam cooperably associated with said plurality of sensing slides of said accumulator wheels, and b. a fixed first pulley associated with a second shaft journaled in said pair of accumulator frame members, said second shaft providing rotatable support for said reset gears of said accumulator.
 20. The printing calculator defined in claim 11 wherein said second drive shaft actuating means comprises: a. a second spring clutch associated with said constant running motor and with said second drive shaft, said second clutch being cooperably associated also with said first clutch engaging member of said first drive shaft actuating means, b. a second clutch engaging member responsive to said keyboard and effective for contractionally releasing said second spring clutch to thereby couple said constant running motor with said second drive shaft for one revolution thereof, said contractional activation of said second spring clutch being effective also to contractionally activate said first spring clutch by means of said first clutch engaging member, said contractional activation of said first spring clutch being effective to couple said first drive shaft with said constant running motor and to engage said screw engaging stud of said channel-shaped member with said drive screw of said first drive shaft, and b. a third clutch engaging member associated with said second clutch engaging member and responsive to the contractional activation of said first spring clutch to interrupt said revolution of said second drive shaft during said first direction translation of said printing element carrier, said third clutch engaging member being effective also to terminate said interruption in said revolution of said second drive shaft upon completion of said first direction translation of said carrier.
 21. The printing calculator defined in claim 15 wherein said plurality of sensing slides associated with said plurality of accumulator wheels comprises a 0-1 slide and a total-subtotal slide for each accumulating order, each of said 0-1 slides being provided with a single step-like limit stop and each of said total-subtotal slides being provided with four spaced-apart step-like limit stops, the single limit stops of said 0-1 slides serving, during total and subtotal operations, to restrainably limit the upward travel of said second of said pair of indexing slides of said printing element carrier in like manner to said fifth pins of said pin carriage during listing and accumulating operations, and said four limit stops of said total-subtotal slides serving to restrainably limit the upward travel of said first of said indexing slides in like manner to said first, second, third and fourth pins of said pin carriage, said limit stops being disposed in blocking relationship with said pair of indexing slides of said carrier according to the sensed positioning of said slides relative to said accumulator cam wheels, said sensed positioning serving to locate selected type characters of said printing sector in printing position in keeping with the amounts stored in said accumulator wheels.
 22. The printing calculator defined in claim 19 wherein said transfer pinions, carry wheels, cam wheels and read-out wheels of the accumulator are cleared during totaling operations by zeroizing said reset gears thereof, said zeroizing being effectuated by accumulator reset means responsive to said keyboard and associated with said first pulley of said second drive shaft and with said second shaft providing rotational support for said reset gears.
 23. The printing calculator defined in claim 22 wherein said accumulator reset means comprises: a. a pair of splines formed in said second shaft at a 180* apart distance, b. a hub portion fixed to the side surface of each of said reset gears, said hub portion housing a biased and pivotally mounted pawl disposed in cooperating relationship with said splines of said second shaft, and c. a first driven member fixed to one of the extremities of said second shaft, said member having a radially disposed abutting surface.
 24. The printing calculator defined in claim 23 wherein said accumulator reset means additionally comprises: a. a rotatably mounted third shaft axially disposed of said second shaft, b. a second pulley fixed to the outboard extremity of said third shaft, said second pulley being rotatably coupled to said first pulley fixed to said second drive shaft such that said third shaft rotates concurrently with said second drive shaft, c. a driving member fixed to said third shaft in spaced relationship from said second pulley, said driving member having an abutting surface disposed on the periphery thereof, d. a second driven member rotatably mounted on said third shaft, said member having an aperture formed in a disk formation thereof, and having also a hub formation with an extended portion spaced from said portion and connected thereto by a rod, e. a biased pawl member rotatably mounted on said rod of said second driven member, said pawl member having a horizontal portion extending through said aperture of said second driven member and spanning the distance between said abutting surfaces of said driving member and said first driven member, said bias of said pawl member serving to urge said horizontal portion thereof into cooperating relationship with said abutting surfaces, f. a biased stop member normally effective for holding said pawl member in uncoupled relationship with said driving member and said first driven member against the bias of said pawl, and g. means responsive to said keyboard and to the return of said printing element carrier to its home position for releaseably activating said stop member, said release effecting the coupling of said pawl member with said driving member and said first driven member at a predetermined point in the revolution of said second drive shaft to rotate said second shaft and to return said reset gears to their zero positions through the cooperation of said splines and said biased pawls of said reset gear hub portions.
 25. In a printing calculator having a 10-key keyboard and a pin carriage comprised of a plurality of vertically arranged columns of keyboard-depressible pins, and having also a plurality of ordinally arranged accumulator wheels, a translatable printing element carrier providing sequential cooperation with said plurality of pin carriage columns for serially printing keyboard-entered amounts, and providing sequential cooperation with said plurality of accumulator wheels for serially accumulating said keyboard-entered amounts and for serially printing amounts stored in said accumulator wheels.
 26. A translatable printing element carrier for use in a printing calculator having a 10-key keyboard, a pin carriage comprised of a plurality of vertically arranged columns of keyboard-depressible pins, and a plurality of ordinally arranged accumulator wheels, said carrier comprising: a single printing sector providing sequential coopEration with said plurality of pin carriage columns and with said plurality of accumulator wheels for serially printing keyboard-entered and stored amounts, respectively, and a single accumulator actuator coupled with said single printing sector and providing sequential cooperation with said plurality of accumulator wheels for serially accumulating keyboard-entered amounts concurrently with their serial printing.
 27. In a printing calculator having a 10-key keyboard, printing means, and a plurality of ordinally arranged accumulator wheels, the combination comprising: a. a pin carriage including a plurality of columnarly arranged keyboard-depressible pins, each of said columns comprising a total of five pins, and b. a translatable printing element carrier including a single printing sector, a single accumulator actuator, and a pair of indexing slides associated with said printing sector and with said accumulator actuator, a first of said indexing slides being sequentially cooperable with a first, second, third and fourth of said five pins arranged in said pin carriage columns during the translation of said carrier, and a second of said indexing slides being sequentially cooperable with a fifth of said five pins in said columns during said translation, said cooperation of said first and second indexing slides with said five pins in each pin carriage column being effective to serially print digit values ranging from 0 to 9 by means of said single printing sector, and to serially accumulate corresponding digit values in said accumulator wheels by means of said single accumulator actuator.
 28. In a printing calculator having a keyboard, printing means, and a plurality of ordinally arranged accumulator wheels, the combination comprising: a. a first and second sensing slide associated with each order of said accumulator wheels, said first slides being provided with a first, second, third and fourth step-like limit stop, and said second slides being provided with a single step-like limit stop, and b. a translatable printing element carrier including a single printing sector and a pair of indexing slides associated therewith, a first of said indexing slides being sequentially cooperable with said first, second, third and fourth step-like limit stops of said first sensing slides during the translation of said carrier, and a second of said indexing slides being sequentially cooperable with said single step-like limit stops of said second sensing slides during said translation, said cooperation of said first and second indexing slides with said step-like limit stops of said pair of sensing slides being effective to serially print digit values ranging from 0 to 9 by means of said single printing sector, according to the amounts stored in said accumulator wheels and sensed therein by said sensing slides. 